<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>工具集合</title>
    <style>
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        body {
            font-family: 'Microsoft YaHei', 'Segoe UI', Tahoma, sans-serif;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
            min-height: 100vh;
            display: flex;
            align-items: center;
            justify-content: center;
            padding: 20px;
        }

        .container {
            max-width: 1200px;
            width: 100%;
        }

        .header {
            text-align: center;
            margin-bottom: 60px;
            animation: fadeInDown 1s ease-out;
        }

        .header h1 {
            font-size: 56px;
            font-weight: 800;
            color: white;
            text-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
            margin-bottom: 16px;
            letter-spacing: 2px;
        }

        .header p {
            font-size: 20px;
            color: rgba(255, 255, 255, 0.9);
            text-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
        }

        .tools-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
            gap: 40px;
            padding: 20px;
        }

        .tool-card {
            background: white;
            border-radius: 20px;
            padding: 40px;
            box-shadow: 0 20px 60px rgba(0, 0, 0, 0.2);
            transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
            position: relative;
            overflow: hidden;
            cursor: pointer;
            text-decoration: none;
            display: block;
        }

        .tool-card::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            height: 6px;
            background: linear-gradient(90deg, #667eea 0%, #764ba2 100%);
            transform: scaleX(0);
            transition: transform 0.3s ease;
        }

        .tool-card:hover::before {
            transform: scaleX(1);
        }

        .tool-card:hover {
            transform: translateY(-10px) scale(1.02);
            box-shadow: 0 30px 80px rgba(0, 0, 0, 0.3);
        }

        .tool-icon {
            font-size: 80px;
            margin-bottom: 20px;
            display: block;
            transition: transform 0.3s ease;
        }

        .tool-card:hover .tool-icon {
            transform: scale(1.1) rotate(5deg);
        }

        .tool-title {
            font-size: 32px;
            font-weight: 700;
            color: #333;
            margin-bottom: 16px;
            display: flex;
            align-items: center;
            gap: 12px;
        }

        .tool-description {
            font-size: 16px;
            color: #666;
            line-height: 1.6;
            margin-bottom: 24px;
        }

        .tool-features {
            list-style: none;
            margin-bottom: 24px;
        }

        .tool-features li {
            padding: 8px 0;
            color: #555;
            font-size: 14px;
            display: flex;
            align-items: center;
            gap: 8px;
        }

        .tool-features li::before {
            content: '✓';
            color: #4facfe;
            font-weight: bold;
            font-size: 18px;
        }

        .tool-button {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            padding: 14px 32px;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: white;
            border: none;
            border-radius: 10px;
            font-size: 16px;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
        }

        .tool-button:hover {
            transform: translateY(-2px);
            box-shadow: 0 6px 25px rgba(102, 126, 234, 0.6);
        }

        .badge {
            display: inline-block;
            padding: 4px 12px;
            background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
            color: white;
            border-radius: 20px;
            font-size: 12px;
            font-weight: 600;
            text-transform: uppercase;
            letter-spacing: 1px;
        }

        .footer {
            text-align: center;
            margin-top: 60px;
            color: white;
            font-size: 14px;
            opacity: 0.8;
            animation: fadeIn 2s ease-out;
        }

        @keyframes fadeInDown {
            from {
                opacity: 0;
                transform: translateY(-30px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        @keyframes fadeIn {
            from {
                opacity: 0;
            }
            to {
                opacity: 1;
            }
        }

        /* 响应式设计 */
        @media (max-width: 768px) {
            .header h1 {
                font-size: 36px;
            }

            .header p {
                font-size: 16px;
            }

            .tools-grid {
                grid-template-columns: 1fr;
                gap: 30px;
            }

            .tool-card {
                padding: 30px;
            }

            .tool-icon {
                font-size: 60px;
            }

            .tool-title {
                font-size: 24px;
            }
        }

        /* 滚动条样式 */
        ::-webkit-scrollbar {
            width: 10px;
        }

        ::-webkit-scrollbar-track {
            background: rgba(255, 255, 255, 0.1);
            border-radius: 5px;
        }

        ::-webkit-scrollbar-thumb {
            background: rgba(255, 255, 255, 0.3);
            border-radius: 5px;
        }

        ::-webkit-scrollbar-thumb:hover {
            background: rgba(255, 255, 255, 0.5);
        }
    </style>
</head>
<body>
    <div class="container">
        <div class="header">
            <h1>🚀 工具集合</h1>
            <p>强大的在线工具，助力您的工作效率</p>
        </div>

        <div class="tools-grid">
            <!-- 公式管理系统 -->
            <a href="aviator/index.html" class="tool-card">
                <span class="tool-icon">🧮</span>
                <div class="tool-title">
                    公式管理系统
                    <span class="badge">推荐</span>
                </div>
                <div class="tool-description">
                    可视化拖拽设计，轻松创建和管理复杂的数学公式，支持实时计算和公式保存。
                </div>
                <ul class="tool-features">
                    <li>可视化拖拽界面，无需编写代码</li>
                    <li>支持复杂数学表达式计算</li>
                    <li>公式保存与加载功能</li>
                    <li>实时参数调试与结果预览</li>
                </ul>
                <button class="tool-button" onclick="event.preventDefault(); window.location.href='aviator/index.html'">
                    <span>立即使用</span>
                    <span>→</span>
                </button>
            </a>

            <!-- PDF拼接工具 -->
            <a href="pdf/index.html" class="tool-card">
                <span class="tool-icon">📄</span>
                <div class="tool-title">
                    PDF拼接工具
                    <span class="badge">实用</span>
                </div>
                <div class="tool-description">
                    专业的PDF页面拼接工具，支持拖拽操作，自由组合多个PDF文件的页面。
                </div>
                <ul class="tool-features">
                    <li>支持多个PDF文件上传</li>
                    <li>拖拽式页面设计画布</li>
                    <li>灵活的页面变换和裁切</li>
                    <li>一键生成并下载合并后的PDF</li>
                </ul>
                <button class="tool-button" onclick="event.preventDefault(); window.location.href='pdf/index.html'">
                    <span>立即使用</span>
                    <span>→</span>
                </button>
            </a>
        </div>

        <div class="footer">
            <p>© 2024 工具集合 | 让工作更高效</p>
        </div>
    </div>

    <script>
        // 为卡片添加点击效果
        document.querySelectorAll('.tool-card').forEach(card => {
            card.addEventListener('click', function(e) {
                // 添加点击动画效果
                this.style.transform = 'scale(0.98)';
                setTimeout(() => {
                    this.style.transform = '';
                }, 100);
            });
        });

        // 页面加载动画
        window.addEventListener('load', function() {
            const cards = document.querySelectorAll('.tool-card');
            cards.forEach((card, index) => {
                card.style.opacity = '0';
                card.style.transform = 'translateY(30px)';
                setTimeout(() => {
                    card.style.transition = 'all 0.6s ease-out';
                    card.style.opacity = '1';
                    card.style.transform = 'translateY(0)';
                }, index * 150);
            });
        });
    </script>
</body>
</html>

